Fix Java weak reference nullification in MediaSessionAndroid

content/browser/media/session/media_session_android.cc

Index: content/browser/media/session/media_session_android.cc
diff --git a/content/browser/media/session/media_session_android.cc b/content/browser/media/session/media_session_android.cc
index 9d74ab4ac2ed880a7f5555ffd117032fbbfd16c8..b4528529130a51740e75fc0d02eccaa1b6b7da80 100644
--- a/content/browser/media/session/media_session_android.cc
+++ b/content/browser/media/session/media_session_android.cc
@@ -63,8 +63,12 @@ ScopedJavaLocalRef<jobject> GetMediaSessionFromWebContents(
 
 void MediaSessionAndroid::MediaSessionDestroyed() {
   ScopedJavaLocalRef<jobject> j_local_session = GetJavaObject();
-  if (j_local_session.is_null())
+  if (j_local_session.is_null()) {
+    // If the Java MediaSession is already garbage collected, unset the weak
+    // Java reference.
+    j_media_session_.reset();
     return;
+  }
 
   JNIEnv* env = base::android::AttachCurrentThread();
   // The Java object will tear down after this call.